Cliff-Edge Consensus: Agreeing on the Precipice

Abstract

This paper presents a new form of consensus that allows nodes to agree locally on the extent of crashed regions in networks of arbitrary size. One key property of our algorithm is that it shows local complexity, i.e. its cost is independent of the size of the complete system, and only depends on the shape and extent of the crashed region to be agreed upon. In this paper, we motivate the need for such an algorithm, formally define this new consensus problem, propose a fault-tolerant solution, and prove its correctness.

The design of a generalised approach to the programming of systems of systems

“…Tecton-machines can be configured with alternative implementations of service discovery protocols (SDP uPnP, Bluetooth, etc. ], election protocols [4], [16], gossip/epidemic protocols, and security protocols. The ability to dynamically configure a tecton-machine with alternative plug-ins is dependent on the availability of code (re)deployment technology as discussed above.…”

“…In addition, tecton-machines collectively monitor each other to detect crashes of tecton-machines that are supporting coordinator nodes. If such a crash is detected, the remaining tecton-machines use an election protocol plug-in to elect new coordinator nodes [16]. Finally, ongoing changes to <name, value> metadata are gossiped to all tecton-machines, and contactcriteria predicates are evaluated lazily-i.e., when changes are received.…”